text: #import json
  class Beam():
      """A Beam defines a structure member.
  
      A beam is a slender member that is subjected only to transverse loadings.
      It is assumed to have homogeneous properties (e.g. E), with a constant
      cross-section.
  
      Parameters
      ----------
      coord : :obj:`list` of :obj:`float`
          List containing start and end coordinates of structural beam.
      E : float
          Young's modulus of the beam cross-section.
      I : float
          Area moment of inertia of the beam cross-section.
  
      """    
  
  
      def __init__(self, coord, E, I):
          """Constructor method"""     
  
          self.coord = coord
          self.E = E
          self.I = I
  
      @property
      def length(self):
          """:float Returns the length between beam end nodes."""
          return self.coord[1] - self.coord[0]
  
      def __str__(self):
          return f"Coords: {self.coord} \nYoung's modulus: {self.E} \nMoment of inertia: {self.I} \nLength: {self.length}"
      # def __repr__(self):
      #     return json.dumps(self.__dict__)